// Copyright (C) 2006 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.


/**
* @fileoverview
* some functions for browser-side pretty printing of code contained in html.
*
* <p>
* For a fairly comprehensive set of languages see the
* <a href="http://google-code-prettify.googlecode.com/svn/trunk/README.html#langs">README</a>
* file that came with this source.  At a minimum, the lexer should work on a
* number of languages including C and friends, Java, Python, Bash, SQL, HTML,
* XML, CSS, Javascript, and Makefiles.  It works passably on Ruby, PHP and Awk
* and a subset of Perl, but, because of commenting conventions, doesn't work on
* Smalltalk, Lisp-like, or CAML-like languages without an explicit lang class.
* <p>
* Usage: <ol>
* <li> include this source file in an html page via
*   {@code <script type="text/javascript" src="/path/to/prettify.js"></script>}
* <li> define style rules.  See the example page for examples.
* <li> mark the {@code <pre>} and {@code <code>} tags in your source with
*    {@code class=prettyprint.}
*    You can also use the (html deprecated) {@code <xmp>} tag, but the pretty
*    printer needs to do more substantial DOM manipulations to support that, so
*    some css styles may not be preserved.
* </ol>
* That's it.  I wanted to keep the API as simple as possible, so there's no
* need to specify which language the code is in, but if you wish, you can add
* another class to the {@code <pre>} or {@code <code>} element to specify the
* language, as in {@code <pre class="prettyprint lang-java">}.  Any class that
* starts with "lang-" followed by a file extension, specifies the file type.
* See the "lang-*.js" files in this directory for code that implements
* per-language file handlers.
* <p>
* Change log:<br>
* cbeust, 2006/08/22
* <blockquote>
*   Java annotations (start with "@") are now captured as literals ("lit")
* </blockquote>
* @requires console
*/

// JSLint declarations
/*global console, document, navigator, setTimeout, window */

/**
* Split {@code prettyPrint} into multiple timeouts so as not to interfere with
* UI events.
* If set to {@code false}, {@code prettyPrint()} is synchronous.
*/
window['PR_SHOULD_USE_CONTINUATION'] = true;

(function ()
{
    // Keyword lists for various languages.
    // We use things that coerce to strings to make them compact when minified
    // and to defeat aggressive optimizers that fold large string constants.
    var FLOW_CONTROL_KEYWORDS = ["break,continue,do,else,for,if,return,while"];
    var C_KEYWORDS = [FLOW_CONTROL_KEYWORDS, "auto,case,char,const,default," +
      "double,enum,extern,float,goto,int,long,register,short,signed,sizeof," +
      "static,struct,switch,typedef,union,unsigned,void,volatile"];
    var COMMON_KEYWORDS = [C_KEYWORDS, "catch,class,delete,false,import," +
      "new,operator,private,protected,public,this,throw,true,try,typeof"];
    var CPP_KEYWORDS = [COMMON_KEYWORDS, "alignof,align_union,asm,axiom,bool," +
      "concept,concept_map,const_cast,constexpr,decltype," +
      "dynamic_cast,explicit,export,friend,inline,late_check," +
      "mutable,namespace,nullptr,reinterpret_cast,static_assert,static_cast," +
      "template,typeid,typename,using,virtual,where"];
    var JAVA_KEYWORDS = [COMMON_KEYWORDS,
      "abstract,boolean,byte,extends,final,finally,implements,import," +
      "instanceof,null,native,package,strictfp,super,synchronized,throws," +
      "transient"];
    var CSHARP_KEYWORDS = [JAVA_KEYWORDS,
      "as,base,by,checked,decimal,delegate,descending,dynamic,event," +
      "fixed,foreach,from,group,implicit,in,interface,internal,into,is,lock," +
      "object,out,override,orderby,params,partial,readonly,ref,sbyte,sealed," +
      "stackalloc,string,select,uint,ulong,unchecked,unsafe,ushort,var"];
    var COFFEE_KEYWORDS = "all,and,by,catch,class,else,extends,false,finally," +
      "for,if,in,is,isnt,loop,new,no,not,null,of,off,on,or,return,super,then," +
      "true,try,unless,until,when,while,yes";
    var JSCRIPT_KEYWORDS = [COMMON_KEYWORDS,
      "debugger,eval,export,function,get,null,set,undefined,var,with," +
      "Infinity,NaN"];
    var PERL_KEYWORDS = "caller,delete,die,do,dump,elsif,eval,exit,foreach,for," +
      "goto,if,import,last,local,my,next,no,our,print,package,redo,require," +
      "sub,undef,unless,until,use,wantarray,while,BEGIN,END";
    var PYTHON_KEYWORDS = [FLOW_CONTROL_KEYWORDS, "and,as,assert,class,def,del," +
      "elif,except,exec,finally,from,global,import,in,is,lambda," +
      "nonlocal,not,or,pass,print,raise,try,with,yield," +
      "False,True,None"];
    var RUBY_KEYWORDS = [FLOW_CONTROL_KEYWORDS, "alias,and,begin,case,class," +
      "def,defined,elsif,end,ensure,false,in,module,next,nil,not,or,redo," +
      "rescue,retry,self,super,then,true,undef,unless,until,when,yield," +
      "BEGIN,END"];
    var SH_KEYWORDS = [FLOW_CONTROL_KEYWORDS, "case,done,elif,esac,eval,fi," +
      "function,in,local,set,then,until"];
    var ALL_KEYWORDS = [
      CPP_KEYWORDS, CSHARP_KEYWORDS, JSCRIPT_KEYWORDS, PERL_KEYWORDS +
      PYTHON_KEYWORDS, RUBY_KEYWORDS, SH_KEYWORDS];
    var C_TYPES = /^(DIR|FILE|vector|(de|priority_)?queue|list|stack|(const_)?iterator|(multi)?(set|map)|bitset|u?(int|float)\d*)/;

    // token style names.  correspond to css classes
    /**
    * token style for a string literal
    * @const
    */
    var PR_STRING = 'str';
    /**
    * token style for a keyword
    * @const
    */
    var PR_KEYWORD = 'kwd';
    /**
    * token style for a comment
    * @const
    */
    var PR_COMMENT = 'com';
    /**
    * token style for a type
    * @const
    */
    var PR_TYPE = 'typ';
    /**
    * token style for a literal value.  e.g. 1, null, true.
    * @const
    */
    var PR_LITERAL = 'lit';
    /**
    * token style for a punctuation string.
    * @const
    */
    var PR_PUNCTUATION = 'pun';
    /**
    * token style for a punctuation string.
    * @const
    */
    var PR_PLAIN = 'pln';

    /**
    * token style for an sgml tag.
    * @const
    */
    var PR_TAG = 'tag';
    /**
    * token style for a markup declaration such as a DOCTYPE.
    * @const
    */
    var PR_DECLARATION = 'dec';
    /**
    * token style for embedded source.
    * @const
    */
    var PR_SOURCE = 'src';
    /**
    * token style for an sgml attribute name.
    * @const
    */
    var PR_ATTRIB_NAME = 'atn';
    /**
    * token style for an sgml attribute value.
    * @const
    */
    var PR_ATTRIB_VALUE = 'atv';

    /**
    * A class that indicates a section of markup that is not code, e.g. to allow
    * embedding of line numbers within code listings.
    * @const
    */
    var PR_NOCODE = 'nocode';



    /**
    * A set of tokens that can precede a regular expression literal in
    * javascript
    * http://web.archive.org/web/20070717142515/http://www.mozilla.org/js/language/js20/rationale/syntax.html
    * has the full list, but I've removed ones that might be problematic when
    * seen in languages that don't support regular expression literals.
    *
    * <p>Specifically, I've removed any keywords that can't precede a regexp
    * literal in a syntactically legal javascript program, and I've removed the
    * "in" keyword since it's not a keyword in many languages, and might be used
    * as a count of inches.
    *
    * <p>The link a above does not accurately describe EcmaScript rules since
    * it fails to distinguish between (a=++/b/i) and (a++/b/i) but it works
    * very well in practice.
    *
    * @private
    * @const
    */
    var REGEXP_PRECEDER_PATTERN = '(?:^^\\.?|[+-]|\\!|\\!=|\\!==|\\#|\\%|\\%=|&|&&|&&=|&=|\\(|\\*|\\*=|\\+=|\\,|\\-=|\\->|\\/|\\/=|:|::|\\;|<|<<|<<=|<=|=|==|===|>|>=|>>|>>=|>>>|>>>=|\\?|\\@|\\[|\\^|\\^=|\\^\\^|\\^\\^=|\\{|\\||\\|=|\\|\\||\\|\\|=|\\~|break|case|continue|delete|do|else|finally|instanceof|return|throw|try|typeof)\\s*';

    // CAVEAT: this does not properly handle the case where a regular
    // expression immediately follows another since a regular expression may
    // have flags for case-sensitivity and the like.  Having regexp tokens
    // adjacent is not valid in any language I'm aware of, so I'm punting.
    // TODO: maybe style special characters inside a regexp as punctuation.


    /**
    * Given a group of {@link RegExp}s, returns a {@code RegExp} that globally
    * matches the union of the sets of strings matched by the input RegExp.
    * Since it matches globally, if the input strings have a start-of-input
    * anchor (/^.../), it is ignored for the purposes of unioning.
    * @param {Array.<RegExp>} regexs non multiline, non-global regexs.
    * @return {RegExp} a global regex.
    */
    function combinePrefixPatterns(regexs)
    {
        var capturedGroupIndex = 0;

        var needToFoldCase = false;
        var ignoreCase = false;
        for (var i = 0, n = regexs.length; i < n; ++i)
        {
            var regex = regexs[i];
            if (regex.ignoreCase)
            {
                ignoreCase = true;
            } else if (/[a-z]/i.test(regex.source.replace(
                     /\\u[0-9a-f]{4}|\\x[0-9a-f]{2}|\\[^ux]/gi, '')))
            {
                needToFoldCase = true;
                ignoreCase = false;
                break;
            }
        }

        var escapeCharToCodeUnit = {
            'b': 8,
            't': 9,
            'n': 0xa,
            'v': 0xb,
            'f': 0xc,
            'r': 0xd
        };

        function decodeEscape(charsetPart)
        {
            var cc0 = charsetPart.charCodeAt(0);
            if (cc0 !== 92 /* \\ */)
            {
                return cc0;
            }
            var c1 = charsetPart.charAt(1);
            cc0 = escapeCharToCodeUnit[c1];
            if (cc0)
            {
                return cc0;
            } else if ('0' <= c1 && c1 <= '7')
            {
                return parseInt(charsetPart.substring(1), 8);
            } else if (c1 === 'u' || c1 === 'x')
            {
                return parseInt(charsetPart.substring(2), 16);
            } else
            {
                return charsetPart.charCodeAt(1);
            }
        }

        function encodeEscape(charCode)
        {
            if (charCode < 0x20)
            {
                return (charCode < 0x10 ? '\\x0' : '\\x') + charCode.toString(16);
            }
            var ch = String.fromCharCode(charCode);
            if (ch === '\\' || ch === '-' || ch === '[' || ch === ']')
            {
                ch = '\\' + ch;
            }
            return ch;
        }

        function caseFoldCharset(charSet)
        {
            var charsetParts = charSet.substring(1, charSet.length - 1).match(
          new RegExp(
              '\\\\u[0-9A-Fa-f]{4}'
              + '|\\\\x[0-9A-Fa-f]{2}'
              + '|\\\\[0-3][0-7]{0,2}'
              + '|\\\\[0-7]{1,2}'
              + '|\\\\[\\s\\S]'
              + '|-'
              + '|[^-\\\\]',
              'g'));
            var groups = [];
            var ranges = [];
            var inverse = charsetParts[0] === '^';
            for (var i = inverse ? 1 : 0, n = charsetParts.length; i < n; ++i)
            {
                var p = charsetParts[i];
                if (/\\[bdsw]/i.test(p))
                {  // Don't muck with named groups.
                    groups.push(p);
                } else
                {
                    var start = decodeEscape(p);
                    var end;
                    if (i + 2 < n && '-' === charsetParts[i + 1])
                    {
                        end = decodeEscape(charsetParts[i + 2]);
                        i += 2;
                    } else
                    {
                        end = start;
                    }
                    ranges.push([start, end]);
                    // If the range might intersect letters, then expand it.
                    // This case handling is too simplistic.
                    // It does not deal with non-latin case folding.
                    // It works for latin source code identifiers though.
                    if (!(end < 65 || start > 122))
                    {
                        if (!(end < 65 || start > 90))
                        {
                            ranges.push([Math.max(65, start) | 32, Math.min(end, 90) | 32]);
                        }
                        if (!(end < 97 || start > 122))
                        {
                            ranges.push([Math.max(97, start) & ~32, Math.min(end, 122) & ~32]);
                        }
                    }
                }
            }

            // [[1, 10], [3, 4], [8, 12], [14, 14], [16, 16], [17, 17]]
            // -> [[1, 12], [14, 14], [16, 17]]
            ranges.sort(function (a, b) { return (a[0] - b[0]) || (b[1] - a[1]); });
            var consolidatedRanges = [];
            var lastRange = [NaN, NaN];
            for (var i = 0; i < ranges.length; ++i)
            {
                var range = ranges[i];
                if (range[0] <= lastRange[1] + 1)
                {
                    lastRange[1] = Math.max(lastRange[1], range[1]);
                } else
                {
                    consolidatedRanges.push(lastRange = range);
                }
            }

            var out = ['['];
            if (inverse) { out.push('^'); }
            out.push.apply(out, groups);
            for (var i = 0; i < consolidatedRanges.length; ++i)
            {
                var range = consolidatedRanges[i];
                out.push(encodeEscape(range[0]));
                if (range[1] > range[0])
                {
                    if (range[1] + 1 > range[0]) { out.push('-'); }
                    out.push(encodeEscape(range[1]));
                }
            }
            out.push(']');
            return out.join('');
        }

        function allowAnywhereFoldCaseAndRenumberGroups(regex)
        {
            // Split into character sets, escape sequences, punctuation strings
            // like ('(', '(?:', ')', '^'), and runs of characters that do not
            // include any of the above.
            var parts = regex.source.match(
          new RegExp(
              '(?:'
              + '\\[(?:[^\\x5C\\x5D]|\\\\[\\s\\S])*\\]'  // a character set
              + '|\\\\u[A-Fa-f0-9]{4}'  // a unicode escape
              + '|\\\\x[A-Fa-f0-9]{2}'  // a hex escape
              + '|\\\\[0-9]+'  // a back-reference or octal escape
              + '|\\\\[^ux0-9]'  // other escape sequence
              + '|\\(\\?[:!=]'  // start of a non-capturing group
              + '|[\\(\\)\\^]'  // start/emd of a group, or line start
              + '|[^\\x5B\\x5C\\(\\)\\^]+'  // run of other characters
              + ')',
              'g'));
            var n = parts.length;

            // Maps captured group numbers to the number they will occupy in
            // the output or to -1 if that has not been determined, or to
            // undefined if they need not be capturing in the output.
            var capturedGroups = [];

            // Walk over and identify back references to build the capturedGroups
            // mapping.
            for (var i = 0, groupIndex = 0; i < n; ++i)
            {
                var p = parts[i];
                if (p === '(')
                {
                    // groups are 1-indexed, so max group index is count of '('
                    ++groupIndex;
                } else if ('\\' === p.charAt(0))
                {
                    var decimalValue = +p.substring(1);
                    if (decimalValue && decimalValue <= groupIndex)
                    {
                        capturedGroups[decimalValue] = -1;
                    }
                }
            }

            // Renumber groups and reduce capturing groups to non-capturing groups
            // where possible.
            for (var i = 1; i < capturedGroups.length; ++i)
            {
                if (-1 === capturedGroups[i])
                {
                    capturedGroups[i] = ++capturedGroupIndex;
                }
            }
            for (var i = 0, groupIndex = 0; i < n; ++i)
            {
                var p = parts[i];
                if (p === '(')
                {
                    ++groupIndex;
                    if (capturedGroups[groupIndex] === undefined)
                    {
                        parts[i] = '(?:';
                    }
                } else if ('\\' === p.charAt(0))
                {
                    var decimalValue = +p.substring(1);
                    if (decimalValue && decimalValue <= groupIndex)
                    {
                        parts[i] = '\\' + capturedGroups[groupIndex];
                    }
                }
            }

            // Remove any prefix anchors so that the output will match anywhere.
            // ^^ really does mean an anchored match though.
            for (var i = 0, groupIndex = 0; i < n; ++i)
            {
                if ('^' === parts[i] && '^' !== parts[i + 1]) { parts[i] = ''; }
            }

            // Expand letters to groups to handle mixing of case-sensitive and
            // case-insensitive patterns if necessary.
            if (regex.ignoreCase && needToFoldCase)
            {
                for (var i = 0; i < n; ++i)
                {
                    var p = parts[i];
                    var ch0 = p.charAt(0);
                    if (p.length >= 2 && ch0 === '[')
                    {
                        parts[i] = caseFoldCharset(p);
                    } else if (ch0 !== '\\')
                    {
                        // TODO: handle letters in numeric escapes.
                        parts[i] = p.replace(
                /[a-zA-Z]/g,
                function (ch)
                {
                    var cc = ch.charCodeAt(0);
                    return '[' + String.fromCharCode(cc & ~32, cc | 32) + ']';
                });
                    }
                }
            }

            return parts.join('');
        }

        var rewritten = [];
        for (var i = 0, n = regexs.length; i < n; ++i)
        {
            var regex = regexs[i];
            if (regex.global || regex.multiline) { throw new Error('' + regex); }
            rewritten.push(
          '(?:' + allowAnywhereFoldCaseAndRenumberGroups(regex) + ')');
        }

        return new RegExp(rewritten.join('|'), ignoreCase ? 'gi' : 'g');
    }


    /**
    * Split markup into a string of source code and an array mapping ranges in
    * that string to the text nodes in which they appear.
    *
    * <p>
    * The HTML DOM structure:</p>
    * <pre>
    * (Element   "p"
    *   (Element "b"
    *     (Text  "print "))       ; #1
    *   (Text    "'Hello '")      ; #2
    *   (Element "br")            ; #3
    *   (Text    "  + 'World';")) ; #4
    * </pre>
    * <p>
    * corresponds to the HTML
    * {@code <p><b>print </b>'Hello '<br>  + 'World';</p>}.</p>
    *
    * <p>
    * It will produce the output:</p>
    * <pre>
    * {
    *   sourceCode: "print 'Hello '\n  + 'World';",
    *   //                 1         2
    *   //       012345678901234 5678901234567
    *   spans: [0, #1, 6, #2, 14, #3, 15, #4]
    * }
    * </pre>
    * <p>
    * where #1 is a reference to the {@code "print "} text node above, and so
    * on for the other text nodes.
    * </p>
    *
    * <p>
    * The {@code} spans array is an array of pairs.  Even elements are the start
    * indices of substrings, and odd elements are the text nodes (or BR elements)
    * that contain the text for those substrings.
    * Substrings continue until the next index or the end of the source.
    * </p>
    *
    * @param {Node} node an HTML DOM subtree containing source-code.
    * @return {Object} source code and the text nodes in which they occur.
    */
    function extractSourceSpans(node)
    {
        var nocode = /(?:^|\s)nocode(?:\s|$)/;

        var chunks = [];
        var length = 0;
        var spans = [];
        var k = 0;

        var whitespace;
        if (node.currentStyle)
        {
            whitespace = node.currentStyle.whiteSpace;
        } else if (window.getComputedStyle)
        {
            whitespace = document.defaultView.getComputedStyle(node, null)
          .getPropertyValue('white-space');
        }
        var isPreformatted = whitespace && 'pre' === whitespace.substring(0, 3);

        function walk(node)
        {
            switch (node.nodeType)
            {
                case 1:  // Element
                    if (nocode.test(node.className)) { return; }
                    for (var child = node.firstChild; child; child = child.nextSibling)
                    {
                        walk(child);
                    }
                    var nodeName = node.nodeName;
                    if ('BR' === nodeName || 'LI' === nodeName)
                    {
                        chunks[k] = '\n';
                        spans[k << 1] = length++;
                        spans[(k++ << 1) | 1] = node;
                    }
                    break;
                case 3: case 4:  // Text
                    var text = node.nodeValue;
                    if (text.length)
                    {
                        if (!isPreformatted)
                        {
                            text = text.replace(/[ \t\r\n]+/g, ' ');
                        } else
                        {
                            text = text.replace(/\r\n?/g, '\n');  // Normalize newlines.
                        }
                        // TODO: handle tabs here?
                        chunks[k] = text;
                        spans[k << 1] = length;
                        length += text.length;
                        spans[(k++ << 1) | 1] = node;
                    }
                    break;
            }
        }

        walk(node);

        return {
            sourceCode: chunks.join('').replace(/\n$/, ''),
            spans: spans
        };
    }


    /**
    * Apply the given language handler to sourceCode and add the resulting
    * decorations to out.
    * @param {number} basePos the index of sourceCode within the chunk of source
    *    whose decorations are already present on out.
    */
    function appendDecorations(basePos, sourceCode, langHandler, out)
    {
        if (!sourceCode) { return; }
        var job = {
            sourceCode: sourceCode,
            basePos: basePos
        };
        langHandler(job);
        out.push.apply(out, job.decorations);
    }

    var notWs = /\S/;

    /**
    * Given an element, if it contains only one child element and any text nodes
    * it contains contain only space characters, return the sole child element.
    * Otherwise returns undefined.
    * <p>
    * This is meant to return the CODE element in {@code <pre><code ...>} when
    * there is a single child element that contains all the non-space textual
    * content, but not to return anything where there are multiple child elements
    * as in {@code <pre><code>...</code><code>...</code></pre>} or when there
    * is textual content.
    */
    function childContentWrapper(element)
    {
        var wrapper = undefined;
        for (var c = element.firstChild; c; c = c.nextSibling)
        {
            var type = c.nodeType;
            wrapper = (type === 1)  // Element Node
          ? (wrapper ? element : c)
          : (type === 3)  // Text Node
          ? (notWs.test(c.nodeValue) ? element : wrapper)
          : wrapper;
        }
        return wrapper === element ? undefined : wrapper;
    }

    /** Given triples of [style, pattern, context] returns a lexing function,
    * The lexing function interprets the patterns to find token boundaries and
    * returns a decoration list of the form
    * [index_0, style_0, index_1, style_1, ..., index_n, style_n]
    * where index_n is an index into the sourceCode, and style_n is a style
    * constant like PR_PLAIN.  index_n-1 <= index_n, and style_n-1 applies to
    * all characters in sourceCode[index_n-1:index_n].
    *
    * The stylePatterns is a list whose elements have the form
    * [style : string, pattern : RegExp, DEPRECATED, shortcut : string].
    *
    * Style is a style constant like PR_PLAIN, or can be a string of the
    * form 'lang-FOO', where FOO is a language extension describing the
    * language of the portion of the token in $1 after pattern executes.
    * E.g., if style is 'lang-lisp', and group 1 contains the text
    * '(hello (world))', then that portion of the token will be passed to the
    * registered lisp handler for formatting.
    * The text before and after group 1 will be restyled using this decorator
    * so decorators should take care that this doesn't result in infinite
    * recursion.  For example, the HTML lexer rule for SCRIPT elements looks
    * something like ['lang-js', /<[s]cript>(.+?)<\/script>/].  This may match
    * '<script>foo()<\/script>', which would cause the current decorator to
    * be called with '<script>' which would not match the same rule since
    * group 1 must not be empty, so it would be instead styled as PR_TAG by
    * the generic tag rule.  The handler registered for the 'js' extension would
    * then be called with 'foo()', and finally, the current decorator would
    * be called with '<\/script>' which would not match the original rule and
    * so the generic tag rule would identify it as a tag.
    *
    * Pattern must only match prefixes, and if it matches a prefix, then that
    * match is considered a token with the same style.
    *
    * Context is applied to the last non-whitespace, non-comment token
    * recognized.
    *
    * Shortcut is an optional string of characters, any of which, if the first
    * character, gurantee that this pattern and only this pattern matches.
    *
    * @param {Array} shortcutStylePatterns patterns that always start with
    *   a known character.  Must have a shortcut string.
    * @param {Array} fallthroughStylePatterns patterns that will be tried in
    *   order if the shortcut ones fail.  May have shortcuts.
    *
    * @return {function (Object)} a
    *   function that takes source code and returns a list of decorations.
    */
    function createSimpleLexer(shortcutStylePatterns, fallthroughStylePatterns)
    {
        var shortcuts = {};
        var tokenizer;
        (function ()
        {
            var allPatterns = shortcutStylePatterns.concat(fallthroughStylePatterns);
            var allRegexs = [];
            var regexKeys = {};
            for (var i = 0, n = allPatterns.length; i < n; ++i)
            {
                var patternParts = allPatterns[i];
                var shortcutChars = patternParts[3];
                if (shortcutChars)
                {
                    for (var c = shortcutChars.length; --c >= 0; )
                    {
                        shortcuts[shortcutChars.charAt(c)] = patternParts;
                    }
                }
                var regex = patternParts[1];
                var k = '' + regex;
                if (!regexKeys.hasOwnProperty(k))
                {
                    allRegexs.push(regex);
                    regexKeys[k] = null;
                }
            }
            allRegexs.push(/[\0-\uffff]/);
            tokenizer = combinePrefixPatterns(allRegexs);
        })();

        var nPatterns = fallthroughStylePatterns.length;

        /**
        * Lexes job.sourceCode and produces an output array job.decorations of
        * style classes preceded by the position at which they start in
        * job.sourceCode in order.
        *
        * @param {Object} job an object like <pre>{
        *    sourceCode: {string} sourceText plain text,
        *    basePos: {int} position of job.sourceCode in the larger chunk of
        *        sourceCode.
        * }</pre>
        */
        var decorate = function (job)
        {
            var sourceCode = job.sourceCode, basePos = job.basePos;
            /** Even entries are positions in source in ascending order.  Odd enties
            * are style markers (e.g., PR_COMMENT) that run from that position until
            * the end.
            * @type {Array.<number|string>}
            */
            var decorations = [basePos, PR_PLAIN];
            var pos = 0;  // index into sourceCode
            var tokens = sourceCode.match(tokenizer) || [];
            var styleCache = {};

            for (var ti = 0, nTokens = tokens.length; ti < nTokens; ++ti)
            {
                var token = tokens[ti];
                var style = styleCache[token];
                var match = void 0;

                var isEmbedded;
                if (typeof style === 'string')
                {
                    isEmbedded = false;
                } else
                {
                    var patternParts = shortcuts[token.charAt(0)];
                    if (patternParts)
                    {
                        match = token.match(patternParts[1]);
                        style = patternParts[0];
                    } else
                    {
                        for (var i = 0; i < nPatterns; ++i)
                        {
                            patternParts = fallthroughStylePatterns[i];
                            match = token.match(patternParts[1]);
                            if (match)
                            {
                                style = patternParts[0];
                                break;
                            }
                        }

                        if (!match)
                        {  // make sure that we make progress
                            style = PR_PLAIN;
                        }
                    }

                    isEmbedded = style.length >= 5 && 'lang-' === style.substring(0, 5);
                    if (isEmbedded && !(match && typeof match[1] === 'string'))
                    {
                        isEmbedded = false;
                        style = PR_SOURCE;
                    }

                    if (!isEmbedded) { styleCache[token] = style; }
                }

                var tokenStart = pos;
                pos += token.length;

                if (!isEmbedded)
                {
                    decorations.push(basePos + tokenStart, style);
                } else
                {  // Treat group 1 as an embedded block of source code.
                    var embeddedSource = match[1];
                    var embeddedSourceStart = token.indexOf(embeddedSource);
                    var embeddedSourceEnd = embeddedSourceStart + embeddedSource.length;
                    if (match[2])
                    {
                        // If embeddedSource can be blank, then it would match at the
                        // beginning which would cause us to infinitely recurse on the
                        // entire token, so we catch the right context in match[2].
                        embeddedSourceEnd = token.length - match[2].length;
                        embeddedSourceStart = embeddedSourceEnd - embeddedSource.length;
                    }
                    var lang = style.substring(5);
                    // Decorate the left of the embedded source
                    appendDecorations(
              basePos + tokenStart,
              token.substring(0, embeddedSourceStart),
              decorate, decorations);
                    // Decorate the embedded source
                    appendDecorations(
              basePos + tokenStart + embeddedSourceStart,
              embeddedSource,
              langHandlerForExtension(lang, embeddedSource),
              decorations);
                    // Decorate the right of the embedded section
                    appendDecorations(
              basePos + tokenStart + embeddedSourceEnd,
              token.substring(embeddedSourceEnd),
              decorate, decorations);
                }
            }
            job.decorations = decorations;
        };
        return decorate;
    }

    /** returns a function that produces a list of decorations from source text.
    *
    * This code treats ", ', and ` as string delimiters, and \ as a string
    * escape.  It does not recognize perl's qq() style strings.
    * It has no special handling for double delimiter escapes as in basic, or
    * the tripled delimiters used in python, but should work on those regardless
    * although in those cases a single string literal may be broken up into
    * multiple adjacent string literals.
    *
    * It recognizes C, C++, and shell style comments.
    *
    * @param {Object} options a set of optional parameters.
    * @return {function (Object)} a function that examines the source code
    *     in the input job and builds the decoration list.
    */
    function sourceDecorator(options)
    {
        var shortcutStylePatterns = [], fallthroughStylePatterns = [];
        if (options['tripleQuotedStrings'])
        {
            // '''multi-line-string''', 'single-line-string', and double-quoted
            shortcutStylePatterns.push(
          [PR_STRING, /^(?:\'\'\'(?:[^\'\\]|\\[\s\S]|\'{1,2}(?=[^\']))*(?:\'\'\'|$)|\"\"\"(?:[^\"\\]|\\[\s\S]|\"{1,2}(?=[^\"]))*(?:\"\"\"|$)|\'(?:[^\\\']|\\[\s\S])*(?:\'|$)|\"(?:[^\\\"]|\\[\s\S])*(?:\"|$))/,
           null, '\'"']);
        } else if (options['multiLineStrings'])
        {
            // 'multi-line-string', "multi-line-string"
            shortcutStylePatterns.push(
          [PR_STRING, /^(?:\'(?:[^\\\']|\\[\s\S])*(?:\'|$)|\"(?:[^\\\"]|\\[\s\S])*(?:\"|$)|\`(?:[^\\\`]|\\[\s\S])*(?:\`|$))/,
           null, '\'"`']);
        } else
        {
            // 'single-line-string', "single-line-string"
            shortcutStylePatterns.push(
          [PR_STRING,
           /^(?:\'(?:[^\\\'\r\n]|\\.)*(?:\'|$)|\"(?:[^\\\"\r\n]|\\.)*(?:\"|$))/,
           null, '"\'']);
        }
        if (options['verbatimStrings'])
        {
            // verbatim-string-literal production from the C# grammar.  See issue 93.
            fallthroughStylePatterns.push(
          [PR_STRING, /^@\"(?:[^\"]|\"\")*(?:\"|$)/, null]);
        }
        var hc = options['hashComments'];
        if (hc)
        {
            if (options['cStyleComments'])
            {
                if (hc > 1)
                {  // multiline hash comments
                    shortcutStylePatterns.push(
              [PR_COMMENT, /^#(?:##(?:[^#]|#(?!##))*(?:###|$)|.*)/, null, '#']);
                } else
                {
                    // Stop C preprocessor declarations at an unclosed open comment
                    shortcutStylePatterns.push(
              [PR_COMMENT, /^#(?:(?:define|elif|else|endif|error|ifdef|include|ifndef|line|pragma|undef|warning)\b|[^\r\n]*)/,
               null, '#']);
                }
                fallthroughStylePatterns.push(
            [PR_STRING,
             /^<(?:(?:(?:\.\.\/)*|\/?)(?:[\w-]+(?:\/[\w-]+)+)?[\w-]+\.h|[a-z]\w*)>/,
             null]);
            } else
            {
                shortcutStylePatterns.push([PR_COMMENT, /^#[^\r\n]*/, null, '#']);
            }
        }
        if (options['cStyleComments'])
        {
            fallthroughStylePatterns.push([PR_COMMENT, /^\/\/[^\r\n]*/, null]);
            fallthroughStylePatterns.push(
          [PR_COMMENT, /^\/\*[\s\S]*?(?:\*\/|$)/, null]);
        }
        if (options['regexLiterals'])
        {
            /**
            * @const
            */
            var REGEX_LITERAL = (
            // A regular expression literal starts with a slash that is
            // not followed by * or / so that it is not confused with
            // comments.
          '/(?=[^/*])'
            // and then contains any number of raw characters,
          + '(?:[^/\\x5B\\x5C]'
            // escape sequences (\x5C),
          + '|\\x5C[\\s\\S]'
            // or non-nesting character sets (\x5B\x5D);
          + '|\\x5B(?:[^\\x5C\\x5D]|\\x5C[\\s\\S])*(?:\\x5D|$))+'
            // finally closed by a /.
          + '/');
            fallthroughStylePatterns.push(
          ['lang-regex',
           new RegExp('^' + REGEXP_PRECEDER_PATTERN + '(' + REGEX_LITERAL + ')')
           ]);
        }

        var types = options['types'];
        if (types)
        {
            fallthroughStylePatterns.push([PR_TYPE, types]);
        }

        var keywords = ("" + options['keywords']).replace(/^ | $/g, '');
        if (keywords.length)
        {
            fallthroughStylePatterns.push(
          [PR_KEYWORD,
           new RegExp('^(?:' + keywords.replace(/[\s,]+/g, '|') + ')\\b'),
           null]);
        }

        shortcutStylePatterns.push([PR_PLAIN, /^\s+/, null, ' \r\n\t\xA0']);
        fallthroughStylePatterns.push(
        // TODO(mikesamuel): recognize non-latin letters and numerals in idents
        [PR_LITERAL, /^@[a-z_$][a-z_$@0-9]*/i, null],
        [PR_TYPE, /^(?:[@_]?[A-Z]+[a-z][A-Za-z_$@0-9]*|\w+_t\b)/, null],
        [PR_PLAIN, /^[a-z_$][a-z_$@0-9]*/i, null],
        [PR_LITERAL,
         new RegExp(
             '^(?:'
        // A hex number
             + '0x[a-f0-9]+'
        // or an octal or decimal number,
             + '|(?:\\d(?:_\\d+)*\\d*(?:\\.\\d*)?|\\.\\d\\+)'
        // possibly in scientific notation
             + '(?:e[+\\-]?\\d+)?'
             + ')'
        // with an optional modifier like UL for unsigned long
             + '[a-z]*', 'i'),
         null, '0123456789'],
        // Don't treat escaped quotes in bash as starting strings.  See issue 144.
        [PR_PLAIN, /^\\[\s\S]?/, null],
        [PR_PUNCTUATION, /^.[^\s\w\.$@\'\"\`\/\#\\]*/, null]);

        return createSimpleLexer(shortcutStylePatterns, fallthroughStylePatterns);
    }

    var decorateSource = sourceDecorator({
        'keywords': ALL_KEYWORDS,
        'hashComments': true,
        'cStyleComments': true,
        'multiLineStrings': true,
        'regexLiterals': true
    });

    /**
    * Given a DOM subtree, wraps it in a list, and puts each line into its own
    * list item.
    *
    * @param {Node} node modified in place.  Its content is pulled into an
    *     HTMLOListElement, and each line is moved into a separate list item.
    *     This requires cloning elements, so the input might not have unique
    *     IDs after numbering.
    */
    function numberLines(node, opt_startLineNum)
    {
        var nocode = /(?:^|\s)nocode(?:\s|$)/;
        var lineBreak = /\r\n?|\n/;

        var document = node.ownerDocument;

        var whitespace;
        if (node.currentStyle)
        {
            whitespace = node.currentStyle.whiteSpace;
        } else if (window.getComputedStyle)
        {
            whitespace = document.defaultView.getComputedStyle(node, null)
          .getPropertyValue('white-space');
        }
        // If it's preformatted, then we need to split lines on line breaks
        // in addition to <BR>s.
        var isPreformatted = whitespace && 'pre' === whitespace.substring(0, 3);

        var li = document.createElement('LI');
        while (node.firstChild)
        {
            li.appendChild(node.firstChild);
        }
        // An array of lines.  We split below, so this is initialized to one
        // un-split line.
        var listItems = [li];

        function walk(node)
        {
            switch (node.nodeType)
            {
                case 1:  // Element
                    if (nocode.test(node.className)) { break; }
                    if ('BR' === node.nodeName)
                    {
                        breakAfter(node);
                        // Discard the <BR> since it is now flush against a </LI>.
                        if (node.parentNode)
                        {
                            node.parentNode.removeChild(node);
                        }
                    } else
                    {
                        for (var child = node.firstChild; child; child = child.nextSibling)
                        {
                            walk(child);
                        }
                    }
                    break;
                case 3: case 4:  // Text
                    if (isPreformatted)
                    {
                        var text = node.nodeValue;
                        var match = text.match(lineBreak);
                        if (match)
                        {
                            var firstLine = text.substring(0, match.index);
                            node.nodeValue = firstLine;
                            var tail = text.substring(match.index + match[0].length);
                            if (tail)
                            {
                                var parent = node.parentNode;
                                parent.insertBefore(
                    document.createTextNode(tail), node.nextSibling);
                            }
                            breakAfter(node);
                            if (!firstLine)
                            {
                                // Don't leave blank text nodes in the DOM.
                                node.parentNode.removeChild(node);
                            }
                        }
                    }
                    break;
            }
        }

        // Split a line after the given node.
        function breakAfter(lineEndNode)
        {
            // If there's nothing to the right, then we can skip ending the line
            // here, and move root-wards since splitting just before an end-tag
            // would require us to create a bunch of empty copies.
            while (!lineEndNode.nextSibling)
            {
                lineEndNode = lineEndNode.parentNode;
                if (!lineEndNode) { return; }
            }

            function breakLeftOf(limit, copy)
            {
                // Clone shallowly if this node needs to be on both sides of the break.
                var rightSide = copy ? limit.cloneNode(false) : limit;
                var parent = limit.parentNode;
                if (parent)
                {
                    // We clone the parent chain.
                    // This helps us resurrect important styling elements that cross lines.
                    // E.g. in <i>Foo<br>Bar</i>
                    // should be rewritten to <li><i>Foo</i></li><li><i>Bar</i></li>.
                    var parentClone = breakLeftOf(parent, 1);
                    // Move the clone and everything to the right of the original
                    // onto the cloned parent.
                    var next = limit.nextSibling;
                    parentClone.appendChild(rightSide);
                    for (var sibling = next; sibling; sibling = next)
                    {
                        next = sibling.nextSibling;
                        parentClone.appendChild(sibling);
                    }
                }
                return rightSide;
            }

            var copiedListItem = breakLeftOf(lineEndNode.nextSibling, 0);

            // Walk the parent chain until we reach an unattached LI.
            for (var parent;
            // Check nodeType since IE invents document fragments.
           (parent = copiedListItem.parentNode) && parent.nodeType === 1; )
            {
                copiedListItem = parent;
            }
            // Put it on the list of lines for later processing.
            listItems.push(copiedListItem);
        }

        // Split lines while there are lines left to split.
        for (var i = 0;  // Number of lines that have been split so far.
         i < listItems.length;  // length updated by breakAfter calls.
         ++i)
        {
            walk(listItems[i]);
        }

        // Make sure numeric indices show correctly.
        if (opt_startLineNum === (opt_startLineNum | 0))
        {
            listItems[0].setAttribute('value', opt_startLineNum);
        }

        var ol = document.createElement('OL');
        ol.className = 'linenums';
        var offset = Math.max(0, ((opt_startLineNum - 1 /* zero index */)) | 0) || 0;
        for (var i = 0, n = listItems.length; i < n; ++i)
        {
            li = listItems[i];
            // Stick a class on the LIs so that stylesheets can
            // color odd/even rows, or any other row pattern that
            // is co-prime with 10.
            li.className = 'L' + ((i + offset) % 10);
            if (!li.firstChild)
            {
                li.appendChild(document.createTextNode('\xA0'));
            }
            ol.appendChild(li);
        }

        node.appendChild(ol);
    }

    /**
    * Breaks {@code job.sourceCode} around style boundaries in
    * {@code job.decorations} and modifies {@code job.sourceNode} in place.
    * @param {Object} job like <pre>{
    *    sourceCode: {string} source as plain text,
    *    spans: {Array.<number|Node>} alternating span start indices into source
    *       and the text node or element (e.g. {@code <BR>}) corresponding to that
    *       span.
    *    decorations: {Array.<number|string} an array of style classes preceded
    *       by the position at which they start in job.sourceCode in order
    * }</pre>
    * @private
    */
    function recombineTagsAndDecorations(job)
    {
        var isIE = /\bMSIE\b/.test(navigator.userAgent);
        var newlineRe = /\n/g;

        var source = job.sourceCode;
        var sourceLength = source.length;
        // Index into source after the last code-unit recombined.
        var sourceIndex = 0;

        var spans = job.spans;
        var nSpans = spans.length;
        // Index into spans after the last span which ends at or before sourceIndex.
        var spanIndex = 0;

        var decorations = job.decorations;
        var nDecorations = decorations.length;
        // Index into decorations after the last decoration which ends at or before
        // sourceIndex.
        var decorationIndex = 0;

        // Remove all zero-length decorations.
        decorations[nDecorations] = sourceLength;
        var decPos, i;
        for (i = decPos = 0; i < nDecorations; )
        {
            if (decorations[i] !== decorations[i + 2])
            {
                decorations[decPos++] = decorations[i++];
                decorations[decPos++] = decorations[i++];
            } else
            {
                i += 2;
            }
        }
        nDecorations = decPos;

        // Simplify decorations.
        for (i = decPos = 0; i < nDecorations; )
        {
            var startPos = decorations[i];
            // Conflate all adjacent decorations that use the same style.
            var startDec = decorations[i + 1];
            var end = i + 2;
            while (end + 2 <= nDecorations && decorations[end + 1] === startDec)
            {
                end += 2;
            }
            decorations[decPos++] = startPos;
            decorations[decPos++] = startDec;
            i = end;
        }

        nDecorations = decorations.length = decPos;

        var decoration = null;
        while (spanIndex < nSpans)
        {
            var spanStart = spans[spanIndex];
            var spanEnd = spans[spanIndex + 2] || sourceLength;

            var decStart = decorations[decorationIndex];
            var decEnd = decorations[decorationIndex + 2] || sourceLength;

            var end = Math.min(spanEnd, decEnd);

            var textNode = spans[spanIndex + 1];
            var styledText;
            if (textNode.nodeType !== 1  // Don't muck with <BR>s or <LI>s
            // Don't introduce spans around empty text nodes.
          && (styledText = source.substring(sourceIndex, end)))
            {
                // This may seem bizarre, and it is.  Emitting LF on IE causes the
                // code to display with spaces instead of line breaks.
                // Emitting Windows standard issue linebreaks (CRLF) causes a blank
                // space to appear at the beginning of every line but the first.
                // Emitting an old Mac OS 9 line separator makes everything spiffy.
                if (isIE) { styledText = styledText.replace(newlineRe, '\r'); }
                textNode.nodeValue = styledText;
                var document = textNode.ownerDocument;
                var span = document.createElement('SPAN');
                span.className = decorations[decorationIndex + 1];
                var parentNode = textNode.parentNode;
                parentNode.replaceChild(span, textNode);
                span.appendChild(textNode);
                if (sourceIndex < spanEnd)
                {  // Split off a text node.
                    spans[spanIndex + 1] = textNode
                    // TODO: Possibly optimize by using '' if there's no flicker.
              = document.createTextNode(source.substring(end, spanEnd));
                    parentNode.insertBefore(textNode, span.nextSibling);
                }
            }

            sourceIndex = end;

            if (sourceIndex >= spanEnd)
            {
                spanIndex += 2;
            }
            if (sourceIndex >= decEnd)
            {
                decorationIndex += 2;
            }
        }
    }


    /** Maps language-specific file extensions to handlers. */
    var langHandlerRegistry = {};
    /** Register a language handler for the given file extensions.
    * @param {function (Object)} handler a function from source code to a list
    *      of decorations.  Takes a single argument job which describes the
    *      state of the computation.   The single parameter has the form
    *      {@code {
    *        sourceCode: {string} as plain text.
    *        decorations: {Array.<number|string>} an array of style classes
    *                     preceded by the position at which they start in
    *                     job.sourceCode in order.
    *                     The language handler should assigned this field.
    *        basePos: {int} the position of source in the larger source chunk.
    *                 All positions in the output decorations array are relative
    *                 to the larger source chunk.
    *      } }
    * @param {Array.<string>} fileExtensions
    */
    function registerLangHandler(handler, fileExtensions)
    {
        for (var i = fileExtensions.length; --i >= 0; )
        {
            var ext = fileExtensions[i];
            if (!langHandlerRegistry.hasOwnProperty(ext))
            {
                langHandlerRegistry[ext] = handler;
            } else if (window['console'])
            {
                console['warn']('cannot override language handler %s', ext);
            }
        }
    }
    function langHandlerForExtension(extension, source)
    {
        if (!(extension && langHandlerRegistry.hasOwnProperty(extension)))
        {
            // Treat it as markup if the first non whitespace character is a < and
            // the last non-whitespace character is a >.
            extension = /^\s*</.test(source)
          ? 'default-markup'
          : 'default-code';
        }
        return langHandlerRegistry[extension];
    }
    registerLangHandler(decorateSource, ['default-code']);
    registerLangHandler(
      createSimpleLexer(
          [],
          [
           [PR_PLAIN, /^[^<?]+/],
           [PR_DECLARATION, /^<!\w[^>]*(?:>|$)/],
           [PR_COMMENT, /^<\!--[\s\S]*?(?:-\->|$)/],
    // Unescaped content in an unknown language
           ['lang-', /^<\?([\s\S]+?)(?:\?>|$)/],
           ['lang-', /^<%([\s\S]+?)(?:%>|$)/],
           [PR_PUNCTUATION, /^(?:<[%?]|[%?]>)/],
           ['lang-', /^<xmp\b[^>]*>([\s\S]+?)<\/xmp\b[^>]*>/i],
    // Unescaped content in javascript.  (Or possibly vbscript).
           ['lang-js', /^<script\b[^>]*>([\s\S]*?)(<\/script\b[^>]*>)/i],
    // Contains unescaped stylesheet content
           ['lang-css', /^<style\b[^>]*>([\s\S]*?)(<\/style\b[^>]*>)/i],
           ['lang-in.tag', /^(<\/?[a-z][^<>]*>)/i]
          ]),
      ['default-markup', 'htm', 'html', 'mxml', 'xhtml', 'xml', 'xsl']);
    registerLangHandler(
      createSimpleLexer(
          [
           [PR_PLAIN, /^[\s]+/, null, ' \t\r\n'],
           [PR_ATTRIB_VALUE, /^(?:\"[^\"]*\"?|\'[^\']*\'?)/, null, '\"\'']
           ],
          [
           [PR_TAG, /^^<\/?[a-z](?:[\w.:-]*\w)?|\/?>$/i],
           [PR_ATTRIB_NAME, /^(?!style[\s=]|on)[a-z](?:[\w:-]*\w)?/i],
           ['lang-uq.val', /^=\s*([^>\'\"\s]*(?:[^>\'\"\s\/]|\/(?=\s)))/],
           [PR_PUNCTUATION, /^[=<>\/]+/],
           ['lang-js', /^on\w+\s*=\s*\"([^\"]+)\"/i],
           ['lang-js', /^on\w+\s*=\s*\'([^\']+)\'/i],
           ['lang-js', /^on\w+\s*=\s*([^\"\'>\s]+)/i],
           ['lang-css', /^style\s*=\s*\"([^\"]+)\"/i],
           ['lang-css', /^style\s*=\s*\'([^\']+)\'/i],
           ['lang-css', /^style\s*=\s*([^\"\'>\s]+)/i]
           ]),
      ['in.tag']);
    registerLangHandler(
      createSimpleLexer([], [[PR_ATTRIB_VALUE, /^[\s\S]+/]]), ['uq.val']);
    registerLangHandler(sourceDecorator({
        'keywords': CPP_KEYWORDS,
        'hashComments': true,
        'cStyleComments': true,
        'types': C_TYPES
    }), ['c', 'cc', 'cpp', 'cxx', 'cyc', 'm']);
    registerLangHandler(sourceDecorator({
        'keywords': 'null,true,false'
    }), ['json']);
    registerLangHandler(sourceDecorator({
        'keywords': CSHARP_KEYWORDS,
        'hashComments': true,
        'cStyleComments': true,
        'verbatimStrings': true,
        'types': C_TYPES
    }), ['cs']);
    registerLangHandler(sourceDecorator({
        'keywords': JAVA_KEYWORDS,
        'cStyleComments': true
    }), ['java']);
    registerLangHandler(sourceDecorator({
        'keywords': SH_KEYWORDS,
        'hashComments': true,
        'multiLineStrings': true
    }), ['bsh', 'csh', 'sh']);
    registerLangHandler(sourceDecorator({
        'keywords': PYTHON_KEYWORDS,
        'hashComments': true,
        'multiLineStrings': true,
        'tripleQuotedStrings': true
    }), ['cv', 'py']);
    registerLangHandler(sourceDecorator({
        'keywords': PERL_KEYWORDS,
        'hashComments': true,
        'multiLineStrings': true,
        'regexLiterals': true
    }), ['perl', 'pl', 'pm']);
    registerLangHandler(sourceDecorator({
        'keywords': RUBY_KEYWORDS,
        'hashComments': true,
        'multiLineStrings': true,
        'regexLiterals': true
    }), ['rb']);
    registerLangHandler(sourceDecorator({
        'keywords': JSCRIPT_KEYWORDS,
        'cStyleComments': true,
        'regexLiterals': true
    }), ['js']);
    registerLangHandler(sourceDecorator({
        'keywords': COFFEE_KEYWORDS,
        'hashComments': 3,  // ### style block comments
        'cStyleComments': true,
        'multilineStrings': true,
        'tripleQuotedStrings': true,
        'regexLiterals': true
    }), ['coffee']);
    registerLangHandler(createSimpleLexer([], [[PR_STRING, /^[\s\S]+/]]), ['regex']);

    function applyDecorator(job)
    {
        var opt_langExtension = job.langExtension;

        try
        {
            // Extract tags, and convert the source code to plain text.
            var sourceAndSpans = extractSourceSpans(job.sourceNode);
            /** Plain text. @type {string} */
            var source = sourceAndSpans.sourceCode;
            job.sourceCode = source;
            job.spans = sourceAndSpans.spans;
            job.basePos = 0;

            // Apply the appropriate language handler
            langHandlerForExtension(opt_langExtension, source)(job);

            // Integrate the decorations and tags back into the source code,
            // modifying the sourceNode in place.
            recombineTagsAndDecorations(job);
        } catch (e)
        {
            if ('console' in window)
            {
                console['log'](e && e['stack'] ? e['stack'] : e);
            }
        }
    }

    /**
    * @param sourceCodeHtml {string} The HTML to pretty print.
    * @param opt_langExtension {string} The language name to use.
    *     Typically, a filename extension like 'cpp' or 'java'.
    * @param opt_numberLines {number|boolean} True to number lines,
    *     or the 1-indexed number of the first line in sourceCodeHtml.
    */
    function prettyPrintOne(sourceCodeHtml, opt_langExtension, opt_numberLines)
    {
        var container = document.createElement('PRE');
        // This could cause images to load and onload listeners to fire.
        // E.g. <img onerror="alert(1337)" src="nosuchimage.png">.
        // We assume that the inner HTML is from a trusted source.
        container.innerHTML = sourceCodeHtml;
        if (opt_numberLines)
        {
            numberLines(container, opt_numberLines);
        }

        var job = {
            langExtension: opt_langExtension,
            numberLines: opt_numberLines,
            sourceNode: container
        };
        applyDecorator(job);
        return container.innerHTML;
    }

    function prettyPrint(opt_whenDone)
    {
        function byTagName(tn) { return document.getElementsByTagName(tn); }
        // fetch a list of nodes to rewrite
        var codeSegments = [byTagName('pre'), byTagName('code'), byTagName('xmp')];
        var elements = [];
        for (var i = 0; i < codeSegments.length; ++i)
        {
            for (var j = 0, n = codeSegments[i].length; j < n; ++j)
            {
                elements.push(codeSegments[i][j]);
            }
        }
        codeSegments = null;

        var clock = Date;
        if (!clock['now'])
        {
            clock = { 'now': function () { return +(new Date); } };
        }

        // The loop is broken into a series of continuations to make sure that we
        // don't make the browser unresponsive when rewriting a large page.
        var k = 0;
        var prettyPrintingJob;

        var langExtensionRe = /\blang(?:uage)?-([\w.]+)(?!\S)/;
        var prettyPrintRe = /\bprettyprint\b/;

        function doWork()
        {
            var endTime = (window['PR_SHOULD_USE_CONTINUATION'] ?
                     clock['now']() + 250 /* ms */ :
                     Infinity);
            for (; k < elements.length && clock['now']() < endTime; k++)
            {
                var cs = elements[k];
                var className = cs.className;
                if (className.indexOf('prettyprint') >= 0)
                {
                    // If the classes includes a language extensions, use it.
                    // Language extensions can be specified like
                    //     <pre class="prettyprint lang-cpp">
                    // the language extension "cpp" is used to find a language handler as
                    // passed to PR.registerLangHandler.
                    // HTML5 recommends that a language be specified using "language-"
                    // as the prefix instead.  Google Code Prettify supports both.
                    // http://dev.w3.org/html5/spec-author-view/the-code-element.html
                    var langExtension = className.match(langExtensionRe);
                    // Support <pre class="prettyprint"><code class="language-c">
                    var wrapper;
                    if (!langExtension && (wrapper = childContentWrapper(cs))
              && "CODE" === wrapper.tagName)
                    {
                        langExtension = wrapper.className.match(langExtensionRe);
                    }

                    if (langExtension)
                    {
                        langExtension = langExtension[1];
                    }

                    // make sure this is not nested in an already prettified element
                    var nested = false;
                    for (var p = cs.parentNode; p; p = p.parentNode)
                    {
                        if ((p.tagName === 'pre' || p.tagName === 'code' ||
                 p.tagName === 'xmp') &&
                p.className && p.className.indexOf('prettyprint') >= 0)
                        {
                            nested = true;
                            break;
                        }
                    }
                    if (!nested)
                    {
                        // Look for a class like linenums or linenums:<n> where <n> is the
                        // 1-indexed number of the first line.
                        var lineNums = cs.className.match(/\blinenums\b(?::(\d+))?/);
                        lineNums = lineNums
                  ? lineNums[1] && lineNums[1].length ? +lineNums[1] : true
                  : false;
                        if (lineNums) { numberLines(cs, lineNums); }

                        // do the pretty printing
                        prettyPrintingJob = {
                            langExtension: langExtension,
                            sourceNode: cs,
                            numberLines: lineNums
                        };
                        applyDecorator(prettyPrintingJob);
                    }
                }
            }
            if (k < elements.length)
            {
                // finish up in a continuation
                setTimeout(doWork, 250);
            } else if (opt_whenDone)
            {
                opt_whenDone();
            }
        }

        doWork();
    }

    /**
    * Find all the {@code <pre>} and {@code <code>} tags in the DOM with
    * {@code class=prettyprint} and prettify them.
    *
    * @param {Function?} opt_whenDone if specified, called when the last entry
    *     has been finished.
    */
    window['prettyPrintOne'] = prettyPrintOne;
    /**
    * Pretty print a chunk of code.
    *
    * @param {string} sourceCodeHtml code as html
    * @return {string} code as html, but prettier
    */
    window['prettyPrint'] = prettyPrint;
    /**
    * Contains functions for creating and registering new language handlers.
    * @type {Object}
    */
    window['PR'] = {
        'createSimpleLexer': createSimpleLexer,
        'registerLangHandler': registerLangHandler,
        'sourceDecorator': sourceDecorator,
        'PR_ATTRIB_NAME': PR_ATTRIB_NAME,
        'PR_ATTRIB_VALUE': PR_ATTRIB_VALUE,
        'PR_COMMENT': PR_COMMENT,
        'PR_DECLARATION': PR_DECLARATION,
        'PR_KEYWORD': PR_KEYWORD,
        'PR_LITERAL': PR_LITERAL,
        'PR_NOCODE': PR_NOCODE,
        'PR_PLAIN': PR_PLAIN,
        'PR_PUNCTUATION': PR_PUNCTUATION,
        'PR_SOURCE': PR_SOURCE,
        'PR_STRING': PR_STRING,
        'PR_TAG': PR_TAG,
        'PR_TYPE': PR_TYPE
    };
})();